AlN Two-Dimensional-Mode Resonators for Ultra-High Frequency Applications

Abstract

In this letter, we present the first prototype of aluminum nitride two-dimensional-mode resonators (2DMRs) for operation in the ultra-high-frequency range. The 2DMRs in this letter are made of thick AlN films ( ${5.9} \mu \text{m}$ ) and rely on both the $ {d} _{31}$ and the $ {d}_{33}$ coefficients of AlN to attain high electromechanical coupling ( $ {k} _{t}^{2}$ ), low motional resistance, and a limited lithographic control of the resonance frequency. $ {k} _{t}^{2 } > 3.4$ %, a mechanical quality factor larger than 2400, and >10% lithographic variation of the center frequency were demonstrated.